For creating LV2 UI's I end up more and more writing the same code, so I
decided to wrote a Layer for it.
It's supposed to create, manage, draw, and destroy X11 widgets with a
cairo surface to draw.
Additional to subscribe to and handle events.
I decided to put it in the Public Domain, so everyone could do what ever
he /she want's with it.
The repository contain a example folder showing some of the features
supported by the layer.
It's a tiny, but powerful abstraction of the X11 low level API to easier
the process to create nice GUI's.
Documentation is included in the source code, it's a single header and a
single c file.
All together just 654 lines, were most lines taken by documentation.
So, here you go:
I'm writing a driver for a device which clears the BAR DMA buffer if I send
the Start IO command to it. I'm not sure how to workaround this issue.
I have got the driver working to some extent by moving the Start IO command
code to the open() callback instead of the trigger(SNDRV_PCM_TRIGGER_START)
however that's obviously a hack and causes issues (the first ~0.1s of audio
I also tried to memcpy() the memory to a temporary buffer in the
SNDRV_PCM_TRIGGER_START trigger, however that turned out to be a
performance bottleneck (it took about ~300ms to copy that memory back,
which is ~the period size, probably related).
I'm also aware that using some sort of a copy buffer could work, but that
sounds like a performance waste as it's not needed after the playback is
I tried to search for existing kernel drivers utilizing a similar mechanism
(there's the SNDRV_PCM_INFO_DOUBLE flag after all), but could not find any
results that made sense.
Any help is appreciated.
I have been tinkering with Steve Harris' meterbridge 0.9.2 for jack.
1. Refactored global variables so that the code builds on Debian 9.2.
2. Improved (?) the dpm IEC scale and ballistics.
3. Changed the PPM ballistics to use Fons Adriaensen's JMeters algorithm.
I do however have a deeper question: what is the point of jack meterbridge?
Given that the broadcast and podcast industry has moved to EBU-R128 and
Ebumeter offers EBU R-128 metering. JMeters offers "nostalgia" PPM and VU
meters with correct ballistics, more options, better graphics. The only
thing missing would be a 4x oversampling true peak meter.
Should meterbridge be maintained or should another metering app de bundled
Note that I am not a C engineer, my background is Java and Python. Please
send code review comments and shout if you see anything horrific.
Let me know your thoughts.
Sent from: http://linux-audio.4202.n7.nabble.com/linux-audio-dev-f58952.html
spectmorph-0.5.0 has been released.
Overview of Changes in spectmorph-0.5.0:
* Support user defined instruments
- graphical instrument editor
- new WavSource operator
* Make standard instrument set smaller (less download/disk usage)
* Graphical ADSR editor
* Added "SpectMorph User Manual" (online: html/pdf)
* Use different colors for active/used/unused operators
* LV2 now requires instance access feature
* Add file dialog wrapper shell scripts to work with some ardour bundles
* Integrate XML (pugixml) and ZIP (minizip) 3rd party code
* Minor fixes and cleanups
What is SpectMorph?
SpectMorph is a free software project which allows to analyze samples of
musical instruments, and to combine them (morphing). It can be used to
construct hybrid sounds, for instance a sound between a trumpet and a
flute; or smooth transitions, for instance a sound that starts as a
trumpet and then gradually changes to a flute.
SpectMorph ships with many ready-to-use instruments which can be
combined using morphing.
SpectMorph is implemented in C++ and licensed under the GNU LGPL version 3
Integrating SpectMorph into your Work
SpectMorph is currently available for Linux and Windows users. Here is a
quick overview of how you can make music using SpectMorph.
- VST Plugin, especially for proprietary solutions that don't support LV2.
(Available on Linux and 64-bit Windows)
- LV2 Plugin, for any sequencer that supports it.
- JACK Client.
Note that at this point, we may still change the way sound synthesis
works, so newer versions of SpectMorph may sound (slightly) different
than the current version.
There are many audio demos on the website, which demonstrate morphing
Stefan Westerfeld, Hamburg/Germany, http://space.twc.de/~stefan
DrumGizmo 0.9.17 Released!
DrumGizmo is an open source, multichannel, multilayered, cross-platform
drum plugin and stand-alone application. It enables you to compose drums
in midi and mix them with a multichannel approach. It is comparable to
that of mixing a real drumkit that has been recorded with a multimic setup.
In this release we tried to jam in as many of our planned changes to the
xml as possible. There are still a few more to go but this release has
brought us a large step closer to our feature-complete xml format. Quite
a few other major features has also found their way into this release,
which will be much more visible (and audible) to the users.
Improved sample selection algorithm.
Directed choke functionality.
Drumkit metadata support.
Experimental Cocoa UI support for MacOSX.
Also some bug fixes and a lot of code refactoring (replaced eXpat with
pugixml for one).
For a detailed description of all the new shiny features, including
audio samples and lots of screenshots, see the changelog for 0.9.17 .
And now, without further ado, go grab 0.9.17 
We are glad to announce the release of SoundTracker 1.0.0-pre1 today.
You can download it here: https://sourceforge.net/projects/soundtracker/files/
This is the first release since 2006, when GTK+1-based SoundTracker 0.6.8 had
been released. The major update in this new version is the use of the GTK+ 2
By the way, a GTK+ 3 port of SoundTracker is also available, but not yet
released. Find the Git branch on SourceForge.
Best regards,SoundTracker developers.
What is new in soundtracker-1.0.0-pre1 (06-Jul-2019):
* Interface ported to Gtk+-2 (stephanek / mshatlev / yaliaev)
* Numerous fixes and improvements (mshatlev / binnocenti / yaliaev)
* Alsa 1.x playback and samling drivers, contemporary Jack driver (yaliaev)
* Configurable tracker colors (yaliaev)
* Polyphonic trying mode (yaliaev)
* Sampling drivers now works in a separate thread to be more robust (yaliaev)
* Updated for latest autoconf, automake and gettext
* Updated ru translation (yalaev)
* Note that some keybindings have changed:
- default keybindings for the fast access of channels 16--31 now uses Alt + Shift
modifiers instead of Ctrl
- muting and unmuting channels is performed by pressing Ctrl + M when the cursor
is at the selected channel
- transposition is performed by pressing Alt + = (halftone up), Alt + - (halftone
down), Alt + + (octave
up), Alt + _ (octave down) instead of Alt + q / Alt + a / Alt + Shift + q / Alt +
Shift + a
on 16/17 July we will be holding
a Symposium and Concert with a focus on
experimental interfaces and performances
at SIM, Berlin:
Hoping to see you there
Henrik von Coler
Elektronisches Studio, Fachgebiet Audiokommunikation
Electronic Music Studio, Audio Communication Group
Technische Universität Berlin
Fakultät I Geistes- und Bildungswissenschaften
Institut für Sprache und Kommunikation
Faculty I Humanities
Institute of Speech and Communication
Einsteinufer 17c, Sekr. EN 8, 10587 Berlin
Tel: +49 (0)30 314 22327
Fax: +49 (0)30 314 21143